Froome hit with time penalty but still extends Tour lead

Froome was hit with a time penalty after taking food in the final 5km of the eagely-anticipated 18th stage, which included a double ascent of the fabled Alpe d'Huez.

France's Christophe Riblon won the showpiece stage while Froome finished 57 seconds ahead of second-placed Alberto Contador - and, even after his penalty, extended his advantage to five minutes and 11 seconds.

But some said taking food was a calculated breaking of the rules, Froome's team-mate Richie Porte dropped back to grab an energy bar and the time he was docked probably more than accounted for the time he would have lost had he not taken on a much-needed sugar rush.

"It was a difficult stage," admitted Froome, who is bidding to become the second British rider in succession to win the race, following Sir Bradley Wiggins's triumph in 2012.

"When I signalled for help, I needed sugar and I was thankful that Richie was there.

"I was just getting in as best I could in those last few kilometres. I'm not sure if it made any difference at that point in the race."

And Froome claims Friday's 204km 19th stage, which include four tough climbs - including the Col du Glandon and Col de la Madeleine - will be even tougher.